Adding and Subtracting Fractions with Unlike Denominators

Adding:
When adding you first have to multiply the first denominator by the second one and the second one by the first denominator or if one of the denominators can equally be multiplied to turn into the same denominator as the other, you can just multiply the fraction by that number which will make the numerator change also. By doing this both fractions will have like denominators now and you can add the numerators together to get the answer. If the answer is not yet in lowest terms you just have to divide.
5/12 + 2/6 = 3/4
2/6 x 2/2 = 4/12
4/12 + 5/12 = 9/12 ÷ 3 = 3/4

Subtracting:
When subtracting (just like adding) you first have to change the unlike denominators to like denominators before starting to actually subtract. So I just multiplied 2/3 by 5/5 to make the denominator the same because 3 can be multiplied 5 times to get 15. After subtracting you need to put the answer in lowest terms if it is not in lowest terms.
2/3 - 7/15 = 1/5
2/3 x 5/5 = 10/15
10/15 - 7/15 = 3/15 ÷ 3 = 1/5